JPH01118219A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve short-wavelength recording performance and uniformity by setting the incident angle of an electron beam to be used for heating of a ferromagnetic metallic material in a refractory vessel at >=45 deg. and forming a thin ferromagnetic metallic film by a part of the vapor flow formed by evaporation of the ferromagnetic metallic material. CONSTITUTION:The incident angle of the electron beam 8 to be used for heating of the ferromagnetic metallic material 6 in the refractory vessel 5 is set at >=45 deg.. The thin ferromagnetic metallic film is formed of a part of the vapor flow obtd. by evaporation of the ferromagnetic metallic material 6 on a substrate 1 constituted by coating the fine particles of SiO2 on a polyethylene terephthalate film. The magnetic recording medium having the excellent short- wavelength performance and the good uniformity is thus produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a magnetic recording medium having a magnetic recording layer made of a ferromagnetic metal thin film suitable for high-density magnetic recording.

Conventional technology In recent years, there has been remarkable progress in high-density magnetic recording technology, and it is desirable for magnetic recording media to switch to media with ferromagnetic metal thin films as the magnetic recording layer, such as vapor-deposited tapes. It is rare [iiii transaxcons
On Magnetics (I EEE Transact
ions on Magnetics)vowoMAG
-21, No-3, p, p, 1217-1220 (1s
ss)).

Vapor deposition tape is produced by electron beam evaporation, which is an oblique evaporation process in which the incident angle continuously changes in an oxidizing atmosphere while winding a substrate such as a polymer film along a rotating support such as a cylindrical can. It is common to obtain
Publication No. 3-42010.

Special Publication No. 19493, Institute of Electronics and Communication Engineers Magnetic Recording Study Group Material MR8l-2 (1981), etc.]. Oblique evaporation has issues in terms of evaporation efficiency, so in order to obtain the desired characteristics even when depositing a film over a wide range of incident angles, we have applied evaporation in oxygen,
Studies are underway to improve the focusing of the electron beam in order to sharpen the vapor distribution.

Problems to be Solved by the Invention However, it is not possible to manufacture a magnetic tape that uniformly satisfies the performance requirements of magnetic recording, which is becoming shorter in wavelength, by increasing the focus of the electron beam and improving the scanning method, so improvements are desired. Ta.

The present invention was made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a method for manufacturing a magnetic recording medium that ensures uniformity of magnetic properties and thin film microstructure and has good short wavelength recording performance. It is.

Means for Solving the Problems In order to solve the above-mentioned problems, the method for manufacturing a magnetic recording medium of the present invention includes setting the incident angle of the electron beam for heating the ferromagnetic metal material in the refractory container to 45 degrees or more. , a ferromagnetic metal thin film is formed using a portion of the vapor flow obtained by evaporation.

Effect: The above manufacturing method stabilizes the amount and energy of ions contained in the vapor flow, resulting in uniform magnetic properties and thin film microstructure, resulting in the formation of a magnetic recording layer with excellent magnetic recording performance.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of main parts of a vapor deposition apparatus used to carry out the present invention. In Figure 1, 1 is a substrate on which a polymer film or fine particle coating layer such as polyethylene terephthalate or polyphenylene sulfide is arranged, 2 is an unwinding shaft, 3 is a winding shaft, and 4 is a rotation support such as a cylindrical can. It is the body. 5 is a refractory container, which is a horizontally long container extending in a direction perpendicular to the moving direction of the substrate, and is made of MgO.

'120s, ZrO2, etc. containers are used. 6 is Go.

Go-Ni, Go-Mug, Go-Or, Co
-B is a ferromagnetic metal material, A is an electron beam generator, 8 is an electron beam 19 is a mask that determines the minimum incident angle, 1o is a vacuum chamber, and 11 is an evacuation system. In the figure, θe is the incident angle of the electron beam. That is, it is the incident angle with respect to the perpendicular direction to the surface of the ferromagnetic metal material. Although it is a requirement of the present invention that this angle be 45 degrees or more, it is actually difficult to configure the angle to be 80 degrees or more due to its structure, so it is configured within the range of 45 degrees to 70 degrees. The critical significance of 45 degrees is not necessarily clear, but it represents how many degrees the change rate of short wavelength C/H in the examples described below is with respect to the average value in a tape with a length of 100m. As can be seen from FIG. 2, although it is extremely stable in the range of 45 degrees to 80 degrees, the rate of change increases below 45 degrees. The reason why the rate of change is large below 46 degrees is due to the size of the rotating support normally used, the size of the evaporation source, and the positional relationship between the two, and the proportion of ions included in the vapor flow increases beyond 46 degrees. , and since it has a significant effect on the crystal growth of the thin film, it is presumed that an unstable phenomenon occurs (/'C).

In the following, the recording performance of the magnetic recording medium manufactured according to this example will be explained in more detail in comparison with a comparative example.

SiO2 fine particles of 10 m in diameter were placed on a 10 μm thick T'' IJ ethylene terephthalate film.
)-2 density, place a refractory container of MgO, IJ at 40α directly below a cylindrical can with a diameter of 1 m,
Co-Ni (Co: 80 wt%) was melted and evaporated, and deposited to a thickness of 0.1 μm at a minimum incident angle of 43 degrees. During vapor deposition, the oxygen partial pressure was changed from 3X10' (Torr) to 8X
The coercive force was adjusted to 10-5 (Torr) and controlled according to θe so that the coercive force was 1000 (Oe 3). Twenty arbitrary 8 mm tapes were extracted from a film @40α, length 2000 m, and (1 roll The tape length is 6077!)
, Longitudinal C/N using a modified 8mm video deck
The average value (X) and deviation (R) of were measured. The tapes used were each made of perfluoromysostic acid, which was vacuum-deposited by 60 people as a lubricant. The modification points of the 8mm video are the gear tooth j length o, 24μm amorphous alloy,! This is a system in which shorter wavelength recording performance is important because a composite head with a varnish-type ferrite is used and the carrier frequency is changed from 5 (M) to 7.5 (M±) to achieve a wider band. The manufacturing conditions θe, 0/N X and R are summarized in the table below.

(Left below) Umbrella 1 The beam was deflected near the refractory container by a deflection magnetic field and made incident.

The above example was a case of oblique vapor deposition, but Go-O
r, Co-Ti, Co-Ta, Go-W
, Go-Mo.

Even when a perpendicularly magnetized film such as Go-Or-Nb is formed by electron beam evaporation, the C/N can be improved in short wavelength digital recording by improving orientation and ensuring uniformity. confirmed.

Effects of the Invention As described above, the present invention focuses on short wavelength recording performance,
It would be even more effective if a magnetic recording medium with good uniformity could be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a vapor deposition apparatus used to carry out the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the electron beam incident angle and C/N. 1... Polymer film, 4... Cylindrical can, 5... Refractory container, 6... Vapor deposition material,
8...Electron beam. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (1)

[Claims] The incident angle of the electron beam that heats the ferromagnetic metal material in the refractory container is set to 45 degrees or more, and a ferromagnetic metal thin film is formed with a part of the vapor flow obtained by evaporating the ferromagnetic metal material. A method for manufacturing a magnetic recording medium.